要約

The high heat flux components such as plasma facing components of fusion reactors can be damaged in high heat flux conditions under transient events or accidents. In fusion reactors, plasma disruption events accompanied by thermal quench degrade the materials exposed to plasma directly. Specifically, the material erosion including melting and evaporation can threat thermal integrity of reactor. In Korean fusion demonstration reactor (K-DEMO), tungsten was proposed for plasma facing material and pressurized water (15MPa, 290°C inlet) was adopted as coolant. In the present study, one-dimensional phase change simulation module was developed to simulate melting and evaporation of tungsten. The two models including the effective heat capacity method and evaporation model proposed by Hassanein et al. (1984) were adopted to simulate melting and evaporation respectively. On the other hand, in coolant channel, a nuclear reactor safety analysis code, multidimensional analysis of reactor safety (MARS), had been proposed for thermal-hydraulic analyses to predict boiling of coolant as well as critical heat flux (CHF) phenomena which can aggravate the cooling capability. The phase change simulation module was coupled with MARS code to well predict the thermal response of tungsten including cooling channel. As clarifying the simulation problem, the plasma facing component of K-DEMO was proposed and the heat flux of plasma disruption whose value of 600 MW/m2 with 0.1 sec was applied as boundary condition. The transient analysis was performed and major parameters such as melting and evaporation thicknesses were calculated.